Before today's first witness entered court, Trump attorney Chris Kise asked Judge Engoron to postpone today's proceedings after five members of the New York attorney general's team tested positive for COVID-19.

Describing the attorney general's conduct as "beyond irresponsible," Kise said that his team did not get adequate notice about the COVID exposures despite having close contact with positive individuals.

"Nothing else matters except for pursuing President Trump," Kise said. "We have the leading candidate for president of the United States in the courtroom today."

"The attorney general's office knew on Wednesday and didn't tell any of us," defense attorney Clifford Robert said. "We are truly in an outbreak."

Engoron declined to grant their requested delay.

In a statement, a spokesperson for New York Attorney General Letitia James said the state has complied with all CDC guidelines.

"Our office properly notified the court and defendants' counsel, and the court decided to proceed with trial today. If there were any concerns, defendants could wear masks today or at any point, but they have opted not to," the spokesperson said.

Trump called his former lawyer Michael Cohen a "proven liar" and "felon" as Trump entered the courtroom for his civil trial this morning.

"He's a felon, served a lot of time for lying, and we're just going to go in and see and I think you'll see that for yourself," Trump told reporters outside court.

Cohen pleaded guilty in 2018 to two separate criminal cases and eventually spent more than 13 months in prison -- but said that it was Trump who caused him to "follow a path of darkness."

-ABC News' Ricardo Montero contributed to this report.

Exiting his New York City apartment this morning, Michael Cohen told reporters he was "looking forward" to seeing Trump in court.

"It's been five years since we've been in the same room," Cohen said.

Cohen preemptively defended the credibility of his testimony and reiterated that he previously perjured himself "concert with and for the benefit of Donald J. Trump."

"My credibility should not be in question," Cohen said.

-ABC News' Eric Avram contributed to this report.

Donald Trump has arrived in court for the anticipated testimony of his former lawyer Michael Cohen.

New York Attorney General Letitia James is also attending the trial this morning.

James took her usual seat at the front of the courtroom's gallery, directly behind her team of lawyers at the counsel table.

The courtroom itself is nearly at capacity, with attendance matching the number of observers during the trial's opening statements.

State attorney Andrew Amer began his cross-examination of defense expert David Miller by highlighting that his testimony appeared to contradict Miller's own expert report.

During his direct examination, Miller was asked if he has ever seen any insurance underwriters rely on media outlets when reviewing their surety programs.

"Prior to this, no," Miller responded, referencing how underwriters at Zurich cited articles from Forbes and USA Today in their 2021 annual review of Trump's policies.

However, Miller's own report acknowledged that "some underwriters do not require financials and instead use their experience and other means (such as Forbes and USA Today) to satisfy their underwriting needs."

When Amer suggested that the finding in Miller's report appeared to directly contradict his testimony, the defense objected.

"It seems completely inconsistent. What am I missing?" Judge Arthur Engoron responded.

Miller clarified that he has seen underwriters cite external sources like media reports; however, the Zurich document was the first time he specifically saw Forbes and USA Today cited as sources.